An internationalist Islamist organisation is submitting an application to the European court tomorrow in an effort to overturn a ban on its activities in Germany. Hizb ut-Tahrir, or the Party of Liberation, believes that the five-year-old ban is unlawful and argues it should be free to campaign in the country and have all frozen assets released.

Britain has twice considered proscribing Hizb ut-Tahrir, most recently after the July 7 2005 bombings, and decided each time that there were not grounds for doing so. Last week Denmark’s senior state prosecutor also advised that the organisation should not be banned, as it has not breached that country’s constitution.

Prohibited in several Middle Eastern and central Asian countries, Hizb ut-Tahrir operates legally in Israel, and is not banned in any EU country other than Germany. Although membership of the party remains legal in Germany, it has been prohibited from public activity since 2003, on charges of spreading antisemitic propaganda following the publication of a leaflet the previous year.

More recently, Germany has accused the party of breaching the “concept of international understanding” enshrined in the country’s constitution, a charge more usually levelled against parties of the far right.

The party denies it is antisemitic and, says it is against violence and that its aim is to unite Muslim countries into a single state ruled by Islamic law.

Shaker Assem, the party’s spokesman in Germany, said yesterday: “The German government has decided it would rather subvert its own principles by banning a political group, and prohibiting its thoughts, rather than engaging in debate or intellectually challenging it. As recently as this past week the German authorities have continued their policies of harassment, arrest and intimidation of our members.”

The German government is expected to oppose the submission.

Hizb ut-Tahrir’s leaders in the UK are thought to be concerned that a Conservative government might proscribe it. David Cameron challenged Gordon Brown about the party at the prime minister’s first question time 12 months ago, when the former Home Secretary John Reid told MPs that there was “not sufficient evidence” to ban the organisation.